Umar Nala watershed lies between 22°39'59.91” & 22°43'33.93” N latitude and 78°45'0.30” & 78°48'59.38” E Longitude, elevation ranges between 374 and 935 m above mean sea level and covers 2974 ha area (Fig. 1). The watershed falls within the boundary of Narshinghpur, district of Madhya Pradesh. The study area comes under the Central Narmada valley. Average annual rainfall is 1192 mm, temperature varies from 8.2^°C to 42.5^°C of the study area. Soil is clay to loamy in texture.

To prepare the base map of study area Survey of India toposheet 55 J/14 on 1:50000 scale was scanned in .jpg format and used for further processing. Toposheet was first imported and georefrenced in ERDAS Imagine then further GIS operations were made in Arc GIS. Digitization of watershed boundary & its perimeter, sub watersheds boundary & its perimeter, stream network (Fig. 2) and contours (Fig. 3) were done using Arc GIS.

The digitized boundary, streams and contours were further sub divided for the sub watersheds. These initial parameters were used to determine stream frequency (S_f), drainage density (D_d), texture ratio (T), elongation ratio (R_e), circulatory ratio (R_c), form factor (R_f) and bifurcation ratio (R_b) using standard formulae (Table 1).

On the basis of compound (average) rank values prioritization rating of all sub watershed of Umar Nala watershed was determined. The sub watershed with lowest compound rank value was given the highest priority.

Stream ordering was given using Straheler (1964) ordering system. Umar Nala watershed is 5^th order watershed. The sub-watershed 1 to 13 of third order, 14, 15 and 16 forth order and 17^th is of fifth order. The stream network is presented in Fig. 2.

The basic morphometric parameters i.e. number of streams; length of streams, max length of watersheds and its area & perimeter is determined using potential of GIS (Table 2). Morphometric parameters estimated using formulae are presented in Table 3.

Values of bifurcation ratio in sub watersheds ranges between 1.33 for sub watershed 13 and 5.40 for sub watershed 1. So, lower value of R_b of sub watershed 1 shows structurally less disturbed watershed (Sharma et al. 2010). Low value of drainage density i.e. 3.65 (Sub watershed 6) shows the watershed’s highly permeable characteristics. However, high value of D_d of sub watershed 13 (D_d = 17.03) shows its impermeableness of sub watershed (Gajbhiye et al. 2015). Stream frequency varies between 6.62 of sub watershed 6 and 32.56 of sub watershed 11 and has good agreement with drainage density. Texture ratio values of sub watersheds ranges between 1.43 for sub watershed 8 and 5.83 for sub watershed 1.

Form factor values of sub watersheds ranges between 0.17 (sub watershed 9) and 0.68 (sub watershed 7). Lower values of R_f suggests elongavity of watershed and lower peaks of flow for longer duration. Circulatory ratio values varies between 0.21 (sub watershed 16) and 0.82 (sub watershed 2). Elongation ratio values ranges between 0.47 (sub watershed 9) and 0.93 (sub watershed 7).

Relief ratio shows the steepness of watershed. In the present study R_h values of the sub-watersheds vary from 0.07 to 0.35 (Table 2) suggesting gentle slope in the sub watershed 6 and steep slope in sub watershed 13 (Meshram and Sharma, 2018).

Biswas et al. (1999) in their study stated that the parameters i.e. drainage density, stream frequency bifurcation ratio, texture ratio, elongation ratio circulatory ratio, form factor and relief ratio parameters are the erosion risk evaluation parameters which can be used for prioritization of sub-watersheds. Morphometric parameters viz. drainage density, stream frequency, bifurcation ratio, texture ratio and relief ratio parameters have a direct relationship with erodibility, higher the value; more is the erodibility (Sharma et al. 2012). Therefore, for prioritization of sub-watersheds , the highest value of linear and relief parameters was taken as rank 1, and second highest value was taken as rank 2 and so on, and the least value was taken last in rank. Shape parameters such as elongation ratio, circulatory ratio and form factor have an inverse relationship with erodibility lower the value, more is the erodibility (Sharma et al. 2012) . Thus the lowest value of shape parameters was rated as rank 1, next lower value was rated as rank 2 and so on and the highest value was rated last in rank. So, the ranking of the sub-watersheds has been determined by assigning the highest/rank based on highest value in case of linear and relief parameters and lowest value in case of shape parameters (Table 4).

After assigning the ranks based on different parameters, the ranking values for all the linear, relief and shape parameters are added up for each of the sub-watersheds to arrive at compound value (C_p). Based on average value of these parameters, the sub-watershed having the least rating value was assigned highest priority, next higher value was assigned second priority and so on. The sub-watershed which got the highest C_p value was assigned last priority. Hence, on the basis of morphometric analysis sub-watershed 10 falls in the top priority and sub-watershed 7 on the last priority to start the soil conservation work in Umar Nala watershed.

The present study demonstrate the utility of remote sensing and GIS technique in prioritizing subwatersheds based on morphometric analysis. This study has found that sub-watershed 10 falls on the top priority; hence, this prioritization may be taken for soil conservation measures by planners and decision makers for locale-specific planning and development.